The western release ofSuper Mario Bros. 2was based onYume Kōjō: Doki Doki Panic, aFamily Computer Disk Systemgame meant to tie-in withFuji Television‘s media technology expo, called Yume Kōjō (“Dream Factory”). The characters, enemies, and themes of the game were meant to reflect the mascots and theme of the festival.[2]AfterNintendo of Americafound the Japanese version ofSuper Mario Bros. 2(later released internationally asSuper Mario Bros.: The Lost Levels) to be too difficult and similar to its predecessor,Yume Kōjō: Doki Doki Panicwas modified to becomeSuper Mario Bros. 2for release outside of Japan.[3]:2